Fix params allowed_updates on Telegram bot polling whenever it's an array (#1270)

* fix: stringify allowed_updates if it's an array on getUpdates

* docs: update api documentation

Author: alfanzain

doc/api.md

@@ -209,6 +209,7 @@ Emits `message` when a message arrives.
 | [options.polling.autoStart] | <code>Boolean</code> | <code>true</code> | Start polling immediately |
 | [options.polling.params] | <code>Object</code> |  | Parameters to be used in polling API requests.  See https://core.telegram.org/bots/api#getupdates for more information. |
 | [options.polling.params.timeout] | <code>Number</code> | <code>10</code> | Timeout in seconds for long polling. |
+| [options.polling.params.allowed_updates] | <code>Array</code> \| <code>String</code> |  | A JSON-serialized list of the update types you want your bot to receive.  For example, specify ["message", "edited_channel_post", "callback_query"] to only receive updates of these types. |
 | [options.webHook] | <code>Boolean</code> \| <code>Object</code> | <code>false</code> | Set true to enable WebHook or set options |
 | [options.webHook.host] | <code>String</code> | <code>&quot;0.0.0.0&quot;</code> | Host to bind to |
 | [options.webHook.port] | <code>Number</code> | <code>8443</code> | Port to bind to |

src/telegram.js

@@ -130,6 +130,8 @@ class TelegramBot extends EventEmitter {
    * @param {Object} [options.polling.params] Parameters to be used in polling API requests.
    *  See https://core.telegram.org/bots/api#getupdates for more information.
    * @param {Number} [options.polling.params.timeout=10] Timeout in seconds for long polling.
+   * @param {Array<String>|String} [options.polling.params.allowed_updates] A JSON-serialized list of the update types you want your bot to receive.
+   *  For example, specify ["message", "edited_channel_post", "callback_query"] to only receive updates of these types.
    * @param {Boolean|Object} [options.webHook=false] Set true to enable WebHook or set options
    * @param {String} [options.webHook.host="0.0.0.0"] Host to bind to
    * @param {Number} [options.webHook.port=8443] Port to bind to
@@ -923,6 +925,12 @@ class TelegramBot extends EventEmitter {
       /* eslint-enable no-param-reassign, prefer-rest-params */
     }
 
+    // If allowed_updates is present and is an array, stringify it.
+    // If it's already a string (e.g., user did JSON.stringify), leave as is.
+    if (form.allowed_updates) {
+      form.allowed_updates = stringify(form.allowed_updates);
+    }
+
     return this._request('getUpdates', { form });
   }